Halysites from the Silurian Period

Here is an index fossil for the Silurian Period called a Halysites

It was found in central Jefferson County in the state of Kentucky.

Trimerus delphinocephalus Trilobite

Here is a trilobite found by a KYANA Geological Society (www.kyanageo.org) member on a field trip some years ago. It is a Trimerus delphinocephalus (Green) from the Silurian Period. It was found in the Waldron Shale layer in Clark County, Indiana.

This image shows the trilobite in two pieces: part of the head and thorax/back. Maybe it was a molt. See this link for different picture of this same specimen: http://www.kyanageo.org/Fossils/silurian/arthropoda/trimerus_delphinocephalus.jpg

Here is a link that shows another from the same area but it appears fully intact: http://weekstrilobites.com/Trimerus.htm

Trilobite Trimerus Side View

The side view of a Trimerus delphinocephalus found in Clark County, Indiana in the Waldron Shale layer. The creature lived in the Silurian Period. Two more images of this animal can be found in the Fossils of Ohio book on page 108, figures 10 and 11.

Back Side of Trimerus Trilobite

Here is the back thorax of a Trimerus type trilobite from the Silurian period. It is described in more detail on page 98 of the Fossils of Ohio book. According to that description, these trilobites could get to 20 cm in length. This one about 4-6 cm wide. The creature had small eyes about about 13 segments for the thorax.

Ordovician Bryozoan

Here is a Ordovician bryozoan found in the Kope Formation in Carroll County, Kentucky. It has linear tubes attached, three are showing in the picture.

Ordovician Snail

An Ordovician snail found in the Kope Formation in Carroll County, Kentucky. Maybe it is some sort of Cyclonema.

Isotelus Trilobite Feeding Scoop

Here is an Isotelus trilobite feeding scoop, I think. It was found in the Kope Formation in Carroll County, Kentucky. This creature existed in the Ordovician time period.

Cryptolithus Head Plates

Here are several Cryptolithus sp.trilobite remains found in Carroll County, Kentucky. One still has part of its side spine intact. I have wondered what purpose this spine serves being so close to the body and swept back along the side. Is it possible the trilobite propelled itself backwards with its tail like crayfish do today? As if sped backwards this two spines would protect it if it hit something like a rock or hostile creature?

I also wonder about all the holes along the creatures front rim. Are these some sort of sensory mechanism? I have read this creature is blind so it either navigated with antenna or maybe used this hole system as some sort of detection grid. Of course if it lived in a dark environment, eyes are not really that useful.

This creature lived in the Ordovician period and is in the company of remains from bryozoans and crinoid stems.

Devonian Horn Coral - Tabulophyllum zaphrentiforme

Here is a small horn coral (1.5 cm diameter and 4.5 cm length) that is called Tabulophyllum zaphreniforme (Davis). It is found in the Beechwood Member, North Vernon Limestone, Givetian Stage, and was found in Louisville, Kentucky (central Jefferson County), USA.

This horn coral was known by several other names: Amplexus yandelli Rominger 1876 and Blothrophyllum zaphrentiforme Davis 1887.  E.C. Stumm describes it in Silurian and Devonian Corals of the Falls of the Ohio on page 50, "Coralla simple; subcylindrical to narrowly ceratoid with typical rejuvenation seen where epitheca has been removed.  Calyx with steeply sloping walls. Septa 60-74; major extending almost to axis and probably amplexoid; minor short peripheral ridges."

See Plate 102 of the Blothrophyllum zaphrentiforme figures 8-15 in Kentucky Fossil Corals A Monograph of the Fossil Corals of the Silurian and Devonian Rocks of Kentucky by William J. Davis.

It lived in the Middle Devonian Period (397-385 million years ago) in a shallow tropical sea that covered the area of Jefferson County.  Also see this image at the Indiana Memories Database.

Silurian Colonial Coral

Here is an image of Silurian colonial coral. It was found in central Jefferson County, Kentucky.

Eroded Crinoid Stem

Here is a crinoid stem piece from the Mississippian period. It was found at Lake Cumberland, Kentucky.

Cryptolithus Trilobite

Here a Cryptolithus trilobite from the Orodovician time period (438-505 million years ago). It was found in Carroll County, Kentucky. It is part of the head plate (cephalon) with a spine attached.

Conularia

Here is an odd creature that no one quite knows what it really looked like. It left a skeleton that is in the shape of a four sided pyramid with a lot of grooved lines on it. Some think it might be some sort of jellyfish but they have been found with stems.

Maybe some type of crinoid. It is called a Conularia and existed in the Mississippian time period. I believe this one was found in southern Louisville.

Foerstephyllum Colonial Coral

Unknown species of a Foerstephyllum sp. colonial coral found in eastern Jefferson County in the Liberty formation. This coral existed in the Ordovician time period.

Happy 200th birthday to Charles Darwin! Not sure if this coral showed up in any of his research though.

Crinoid Spine Probably Devonian Period

Here is the spine of a crinoid probably from the Devonian period.

Found in Jefferson County, Kentucky.

Horn Coral Growing from Coral Sheet

A small Devonian horn coral growing out of sheet of coral. Fossils found in Jefferson County, Kentucky.

Dalmanites Trilobite

Here is an imprint of a Dalmanites sp. from Silurian period found in Louisville Limestone, Jefferson County, Kentucky.

Silurian Colonial Coral

Here is a colonial coral found with some other Silurian fossils so it must be Silurian. It is from Louisville Limestone located in Jefferson County, Kentucky.

Sideways View of Silurian Halysites Coral

Here is a piece of Louisville Limestone that I think has Halysites in it. It was found in Jefferson County, Kentucky. Fossil from the Silurian period.

Internal Mold of Dalmanites Trilobite

Here is the internal mold of a Dalmanites sp. pygidium found in Louisville Limestone. The fossil was found in Jefferson County, Kentucky.

Silurian Chain Coral - Halysites

A Halysites chain coral protruding from a rock from Louisville Limestone member. It was found in Jefferson County, Kentucky.

Devonian Corals

Here are some corals from the Devonian period found in Clark County, Indiana. These corals are probably Favositidae Emmonsia eximia

Isotelus Trilobite Fragment

Here is an fragment of an Isotelus trilobite from the Ordovician period. Notice all the fine line cracks in its shell. It was found in eastern Jefferson County, Kentucky.

Ordovician Brachiopod (Platystrophia?)

Here is an Ordovician period brachiopod found in eastern Jefferson County, Kentucky. It is possible it is a Platystrophia

Small Ordovician Snail

Here is a small Ordovician snail found in eastern Jefferson County, Kentucky. It is maybe a Cyclonema?

Kentucky Ordovician Brachiopod

Here is an image of a Ordovician period brachiopod found in eastern Jefferson County, Kentucky.